Wind baffle cowl for heater stacks



March 23, 1937. J, R, SMITH WIND BAFFLE COWL FOR HEATER STACKS Filed Aug. 12, 1936 Patented Mar. 23, 1937 Winn BAFFLE oowL FOR imma'smc s" I 1.;

Application August 12, 1936, Serial-No. '5,'14

4 Claims. (61. sc -st) This invention is a wind baflle cowl for the vent pipes of various heating appliances, especially of the type having gas pilot burners.

It frequently happens that these pilots are ex- 5 tinguished because of the undesired up-draft pull generated by various external air currents at the outlet of the vent pipe or stack, especially when the gas pressure falls low and the pilot flame contracts materially.

An object of this invention is to reduce the hazard of extinction of the pilot flame by means of a device which will effectively control the influence of the external air currents at the stack outlets without interfering with the free dis-' charge of fumes from the stack.

Broadly an object is to provide means whereby to so govern the flow of air at the stack outlet that, regardless of the direction from which the air current approaches the stack outlet, it will be caused to follow a straight channel as it moves into and from the cowl and so eliminates downdraft in the. stack as well as avoiding undesirable, up-draft suction in the stack. Particularly, an object is to provide a cowl which will form an effective bafiie to air currents either straight up or straight down, as well as straight across the stack outlet, and. at innumerable oblique angles to the outlet.

Also an object of importance is the provision of a stack cowl of utmost simplicity of combination and of its several parts, wherefore to provide a cowl of very low cost of production and sale price, and, as well, providing a cowl of light weight, of durable structure and compact form and attractive appearance; it consisting essentially of but two, plane, discal, sheet metal elements.

The invention embodies certain advancements in this art as set forth in the ensuing disclosure and having, with the above, additional objects and advantages as hereinafter developed, and whose construction, combination and details of means, and the manner of operation will be made manifest in the description of the herewith illustrative exposition; it being understood that modifications, variations and adaptations may be resorted to within the scope, principle and spirit of the invention as it is more directly claimed 50 hereinbelow.

Figure l is a broken-away plan of the cowl.

Figure 2 is an elevational, vertical section of the cowl.

The baffle or cowl is made of any suitable ma- 55 terial, preferably stiff sheet metal, and of any size as may be required according to given stack installation.

The cowl shown includes a plane, imperforate, top disc 2 and a plane, lower disc 3, of larger size, which is spaced therebelow and has a centric. circular opening 4 to provide for fume flow from a stack to which the baffle may be directly connected, or connected by means of a complementary collar 5 suitably bracketed to the disc 3.

The discs 2 and 3 are rigidly fixed in spaced, parallel relation by means preferably providing for spatial adjustment as may be required. As here shown sheet-metal, radially disposed, bendable, bowed ties or lugs 6 are fixed between and to the discs 2 and 3, and these latter may be moved apart or toward each other by simply springing the bows. The drawing illustrates a cowl proportioned for eflicient use on a stack of four inches diameter; the disc 3 being of about ten inches diameter and the upper disc 2 of about eight inches. The opening in the lower disc 3 is about five and one-half inches diameter; the spacing between the discs being about threequarters of an inch, though these several dimensions may be departed from.

The top end of the collar 5 (or stack) is fixed in the central opening 4 of the disc, or annulus, 3 in the plane of the latter.

It will be seen that there is exposed a considerable marginal top area of the lower disc 3 beyond the rim of the smaller upper disc 2 and this is an important feature because in the case of down currents of air toward the cowl the air is at once diverted both inward and outward on the disc 3 and no vacuum is formed under the disc 2, and the vacuum formed under the disc 3 is reduced by the down flow of air, from the opening 4 about the collar, supplied by the inflow of air passing inward between the spaced discs 2 and 3. In event of a straight up current against the disc 3 the cycle is reversed and, in either case, little or no suction or up-pull is created in the stack.

From the above it will be obvious that any oblique current of air beats up or down on the margin of the larger disc 3 and in all cases normally resultant vacuum is offset by the sequential, induced current of air into the annular opening 4 between the disc and the coplanar end of the collar 5 (or stack).

What is claimed is:

l. A vent pipe cowl comprising a pair of parallel discs having plane annular portions fixed in spaced relation and the lower disc having a centric, circular opening, and a fume outlet part fixed concentrically in the plane of and of smaller diameter than the said opening whereby to form an annular air flow space between the opening edge of the lower disc and the said part; the 5 lower disc being of materially greater diameter than the upper disc; said perforate larger disc acting as a baflle to air currents about the rim of the smaller, upper disc and providing for flow of air upwardly or downwardly, externally about 10 the coplanarg nd of the said outlet part to thwart the creation of undesired upward draft therein.

2. Awind bafiie cowl for heater stacks including a rigidly fixed pair of spaced, plane, differently sized discs the lower of which is the larger 15 and has an opening larger than and for the coplanar fixture of a given vent pipe part and whereby to form an annular air flow aperture externally of the said part for inflow or outflow of exterior air currents to break the tendency of vacuum creation in the space between the spaced discs by atmospheric air currents.

3. In a stack cowl, a sheet metal disc which is imperforate, and an annulus of substantially larger outside diameter and medially overlapped by and spaced from the disc in fixed relation; the opening in the annulus being larger than the diameter of the given stack.

4. A baflie cowl for a heater stack of about four inches diameter, including a plane, imperforate upper disc of thin inetal and of about eight inches diameter, and an annuluscoaxial therewith and V spaced therebelow about three-quarters of an inch in rigid combination; the hole in the annulus being of about five and one-half inches in diameter, and the outside diameter of the annulus being about ten inches.

JOHN R. SMITH. 

